Associate Program 3 Project Summary The goal of Associate Program 3 is to use and further our understanding of the chemical ecology of coral reef organisms to better inform drug discovery and to provide new and more effective management options for conserving and restoring the diversity and ecological function of coral reefs. We will collaborate with APs 1,2, and 4 to apply ecologically meaningful stresses to species (activation, induction) to enhance the diversity or potency of bioactive metabolites they are producing. Our conservation efforts will focus on further determining the critical role that chemical cues from benthic organisms play in suppressing (seaweeds) or stimulating (corals) recruitment of corals and fishes that must colonize for damaged reefs to recover. We will determine which cuing species are most critical, the variance in response of fishes as a function of trophic group and taxonomy, and whether fishes and corals are responding to the same general cues. Collaborations with AP2 will attempt to identify some of the major metabolites involved. We will scale-up our laboratory and small-scale field experiments to test whether we can initiate reef recovery on scales of 100m2 on degraded reefs in 3 replicate villages on the Coral Coast. This will be accomplished via removal of suppressive seaweeds, addition of stimulatory corals, both, and neither. The recruitment, survival and growth of individual corals will then be followed as will the physical condition and growth rates of newly recruiting fishes. At still larger scales we will evaluate the influence of water-shed scale land use patterns (native vegetation vs introduced mahogany, sugar cane, or oil palm) on chemical cues affecting fish recruitment to adjacent reefs and whether the negative effects of agricultural crops are negated by runoff progressing through coastal mangroves. If so, this provides a management strategy for retaining both coastal agriculture and fishes. At smaller scales, we will conduct metatranscriptomic analyses of the coral host, its zooxanthellae, and its microbiomes through time following coral contact with allelopathic seaweeds to determine the roles of microbially mediated processes in the negative impacts of seaweed on corals. We will cultivate and investigate the roles of microbes from healthy versus stressed corals, test the effects of seaweed extracts on coral-associated bacteria, and assess whether commensal microbes chemically protect corals from microbial pathogens. If so, we will work with AP2 to further investigate the antagonistic interactions and the chemicals involved.